Shock absorber



Sept. 30', 1924. 1,510,185

v A. W. F. MANZEI.

SHOCK ABsoRBER Filed May 12, 1922 6,2 16 e1 liz/'Lig' A l l, 56 52 m 5451 z "MT uff im@ i120 WE Jmzeb,

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Patented sept. 3o, 1924.

UNI- TED STATES PATENT orrica.

AnoLrn w. r. MANZEL', or serrano, NEW Your, AssIeNon rro mANznn anos. oo., on Borrero, NEW Yoan, a conronamronj or NEW Yonx.

snoei: Assouan.

'h Application filed May 12,

To all wlwm it may concern.'

Be it known that I, AnoLrH W. F. MANznL,

a citizen'o the United States, residing at Buffalo, in the county of Erie and 'State of New York, have invented certain new and useful Improvements in Shockl Absorbers, of which the following is a specication.

My invention relates to an improved shock absorber, digned for the purpose of lessening shocks imparted to spring-supported vehicles bodies when caused by the. vehicle traveling over uneven roads; and it relates more particularly to that type of shock absorber whichmay 'be referred' to as a parted thereby to the vehicle body, and also to check the rebounds of the vehicle springs, and consequently the body supported thereby, in traveling over ruts or pronounced projections in the road or when striking obstructions and' passing over the same.

A further object of my invention is to provide a shock absorber in which a Huid, such as oil or the likeis contained, and in which provision is made for maintaining, by simplev means, a restricted passage of a given or -predeterminedarea, which under the,l action of the vehicle springs becomes enlarged in proportion to the compression of said springs 'to allow the free passage of the Huid therethrou h, and recovers its normal size immediatey. compression of said springsA ceases so as to restrict or retard the passage of fluid therethrough during the return movement of said springs toy their normal condition. l

A further object of my. invention is to provide a shock absorber of this type in which a piston is slidably fittedv into a cylinder and novel meansl provided to auto- 1922. serial no. 560,292..

matically seal 'the piston with oil for the purpose of preventing the passage of air `and leakage of oil between the piston and cylinder wall.

A still further object is to provide a shock absorber with two chambers, one of which serves as a -cylinder and has a piston therein, and to locate between said chambers movable co-opera'ting elements serving to regulate the flow of the Huid from one chamber to another under suction created by the pis.- ton, and reversely under pressure of the piston.

A still further object is to provide two movable cooperating elements within a passage connecting two chambers and providing means in one chamber, manipulated under the iniuence of a vehicle spring, to create suction and exert pressure within said asse-ge, one of said elements only being movav le under suction and both being movable under compression, but under varying pressures exerted thereagainst.

With the above and other objects .in view to appear hereinafter,'my invention consists in the novel features of construction, and in the arran ement and combination ofparts l to be hereinafter described and more particularly pointed out in the subjoined claims.

In the drawings y Fig. 1 is a sectlonal elevation of a portion of an automobile or other vehicle having my improved shock absorber applied thereto, the parts of the automobile or vehicle shown being those adjacent the shock absorber. Fig., 2 is a central vertical section through the shock absorber.

Fig. 3 is a horizontal section taken on line 3 3, Fig. 2.

Fig. 4 is a horizontal section taken on line {ir-4, Fig. 2.

Fig. 5 is a horizontal section tak 5--5, Fig. 2.

Fig. 6 is a detached perspective view of the adjustable valve stop.

vFig. 7 is an enlarged vertical on line 7-7, Fig. 2.

In Fig. 1, I have shown the parts of an automobile to which one of my improved absorbers may be applied, and as illustrated,

n on line these parts are at the frontv of the automobile', it being, of course, understood that a shock absorber lis provided at each side of the automobile or other vehicle and that a f ing forced closer to the road surface under spring flexure, with the result that the body of the vehicle, connected to said ends, 1s drawn downwardly. The tendency of the spring to recover after passing over the rough portion or r'ut of the road will throw upv the body of the vehicle, and thereby unduly strain the springs and make riding uncomfortable, oftentimes causing the occupants to be forcibly raised from their seats, only to be dropped back under complete loss of control.

The body and spring, or the axle supporting the spring, may be considered as two relatively movable parts of an automobile, to one of which the body portion or casing of my shock absorber is secured, and to the other of which an element extending from said casing and controlling parts therein is connected. y

The body portionv or casing -is designated b the numeral 13, and it isfdivided in to two c ambers 14, 15 by a vertical curved or segmental wall 16, the chamber 14 being substantially rectangular in cross section while the chamber 15 is cylindrical and serves as a cylinder. The lower ends of the chamber 14 and cylinder 15 are connected by a fluid passagel' and the curved or segmental wall 16 extends upwardly from the wall of said passage and terminates a distance from the upper end of the casing. Above the upper? endl of this wall, the chamber 14 is` in di rect communication with the chamber or cylinder 15, the cylindrical formation of which is continued upwardly to the top of thejcasing. The upper end of the casing is closed by a suitable cover 18, bolted or otherwise fastened to the casing, as at 19,

packin 20 being provided between the up-` per en of the casing and the cover to prevent leakage of oil therebetween.

The cover is provided with a tapped filling opening 21, which is closedwith a screw plug 22,.oil being delivered to the casing through said opening. f

Within the chamber orgcylinder 15 a piston 23 is slidably fitted, said piston being preferably solid and having a reduced lower end 24 to form a downwardly facing shoulder 25 on said piston. Bearing with one end against said shoulder and surrounding said reduced portion 24 is an expansion spring 26, the other or lower end thereof bearing against the bottom 27 of the casing. It is to be noted that the chamber or cylinder 15 is reduced in diameter at its lower end and enlarged in diameter at its upper end; and while the entire chamber is cylindrical and has three different diameters, such a construction isV not absolutely necessary, although by enlarging the upper end or portion of the cylinder, an oil groove 28 is furnished between the wall of said enlarged portion at its lower end and the upper end of the piston, and in this connection I wish to stress the fact that the upper end of the piston is above the bottom of said oil groove vBvhen'in its normal position, as indicated in rlhe piston is fitted to the central or intermediate portion ofthe cylinder, and therefore this portion only need be bored. The upper enlarged portion and the lower rcduced portion of the cylinder may be left unfinished, since the lower reduced portion only enters the reduced lower end of the cylinder, while the piston moves with considerable clearance in the upper enlarged portion.

The upper end of the piston 23 has a circular depression 29 formed therein in which is fitted a hardened steel disk 30, for a purpose to appear hereinafter. The bottoni 27 -of the casing is provided with a tapped drain opening 31, which is closed with a. .screw plug 32 so that the oil within the casing can be conveniently drained whenever it is found necessary or desirable.

In its more restricted sense, the intermediate portion of the chamber or cylinder 15 is the true cylinder for said piston, that portion of the piston extending from the upper reduced portion thereof to the shoulder 25 I preferably refer to as the body of' the piston, and when making reference to the upper end of the piston being in a plane above the bottom of the oil groove 28 when in its lowermostposition, the body portion of the piston is referred to.

The fluid passage 17 is formed by a wall 33 projecting from the wall 16 of the cylinder into the chamber 14 and extending from side wall to side wall, as clearly shown in Fig. 7. The passage 17 is preferably cylindrical and has a stepped reduction in diameter from its outer end inwardly, forming shoulders 34, 35, which are spaced apart, the diameter of the passage between the shoulder 35 and the interior of the cylinder 15 being therefore smaller than the adjacent intermediate portion and said intermediate portion being consequentl f smaller than the outer portion of sai passage, which opens directly into the chamber 14.

Situated inthe intermediate portion of the fluid passage 17 and bearing against the shoulder'35 is a bearing element in the form of a spider. 36 having a stud 37 extending axially therefrom.- The casing vis provided with-an internally lthreaded boss 38, the

axis of which is coincident with that of the and t e outer end thereof being preferably flush with .the ends of the walls of said pas? sage. l'lwtvveen the outerend of said thimble or sleeve and said cap is a spiral spring 42 whichfexelts its force against the outer end :of thethiinble or sleevej41 to maintain the same. against the shoulder 34, but is adapted to be compressed under certain operating conditions, to be .i-lierein'after explained.

` The inner end ofthe thimble or sleeve 41 is internall beveled, and. spaced from the 'walls of said beveled portion is a spherical valve 43 'held 'against an adjustable stop .stud .44. thrintded:l into. andv projecting outwardly and inwardly from the cap 39. This stop stud has an outerthreaded portion 45, an enlarged intermediate portion 46 and-a reduced inner portion 47. SaidV inner portion -47 is of smaller diameter than the youter 'threaded portion and extends into the thimble or sleeve '41, and by reason of its being comparatively small in diameter, oc cupies-but little space centrally within said" thimble or sleeve so as to restrict the passage through ,saidl thimble' orsleeve as little yas possible.

Threaded onto the outer 4projecting end of said stop stud is va lock nut 48 having its innerface recessed to receive packing 49 and thus ard against leakage of oil along the threa s ofsaid stud, said loclr nut when tightened against the c ap -39 retains the stop studin adjusted position. For convenience, the outer end of said stop stud is provided with a lrerf 50 so that it can be conveniently adjusted by usin a screwdriver or other similar tool, the inner end of said'stud determining the space between the thimble or sleeve 41 and the spherical valve '43.

Surrounding the stud 37 of the spider 36 and bearing with one end. against said spider and with its.other\end against the spherical valve 43 is a .spiral spring 51, which is less powerful than the spring 42 surrounding the 'stop stud 40, and when said spring 51 is compressed, as will occur during the upward movement of the piston 23 within its cylinder 15, which action-.hreates suction within the passage 17 and draws the spherical valve 43 inwardly against the action of the spring 51, said valve will be limited in its inward movement by the stud 37.

O11 is delivered into the casing through the filling opening 21 and 'is preferably maintained at a level above the upper end of the piston when in normal position. However, the construction'is of'sucha nature that the operation of the device will be thoroughly edective if the level is below that stated.

Projectlng from the casing 13 are secur-v casino" ing lugs 52 b v .meansof which the may be fastened -to the frame or chassis olf the vehicle, suitable bolts or other fastening means being .provided for the' purpose.

Extending transversely through the casing. is a rock shaft 53, which is integral with a crank or actuating lever 54-extendin from one end of said shaft. lThe shaft is re ducedv at its free end, as at 55, and this re# duced en'd portion is entered into -a cup-like bearing or 'bush-ing 56, of brass or other material, lsaid bearing'or bushing -being fitted into one ofthe sidewalls of the casing and being closed at its outer end and open at its inner end to receive the reduced portion of said shaft. By 'the use of a bushing of this type, leakage ofj'yo'il at this point is prevented. -Inv the opposite side wall a sleeve bushing of brass or other material 57 eov is fitted, and the bore of the casing receiving."-

the sameis enlarged at its outer' end, as at 58, to receive a cup-like washer-retainer 59 in which leather or other washers 60 are located, said washers being packed between the outer end of lsaidv sleeve bushing and the end wall of said cup-like retainer, which latter bears against the hub 6l of the crank or actuating lever 54.

That portion of "the rock shaft positioned between the two side walls lof the casing is eut away or flattened at opposite sides, as at 62, the flattened portions extending from the reduced end portion 55 of said shaft to a point in line or approximatelyl in line with the inner side ofthe opposite wall or to the inner end of the sleeve bushing 57. Mounted on the 'flattened portion of the rock shaftis an actuating arm 63, and

passed through its hub and through said shaft is a pin 64 to secure the two together.

The outer end of this arm is provided with.

upwardly, and by reason of the rock shaft being rotated during the upward movement of said actuating arm, the actuating lever 'p54 is forced upwardly.

the convolutions will be in straight lines,

thus preventing bulging of the spring and assuring an even pressure against the sleeve or thimble 41 at all times.

In Fig. 2 the parts are shown in normal position, and in this position a comparatively small annular space yis provided between the sleeve or thimble 41 and the spherical valve 43, :but it is to be understood that the valve 43 will move inwardly away from the sleeve or thimble 41 under certain conditions, while said sleeve or thimble will move away from the valve under other conditions, to be presently described.

The casing being provided with the necessary quantity of oil or other fluid` it is quite apparent that the fluid will fill the chamber or cylinder 15 to the lower end of the body portin of the piston, also they passage 17, and will reach an equal or higher level in the chamber 14, depending on the quantity of'fluidin the casing. Under normal conditions I prefer that the level of the -fluid beat least even with the upper edge of the curved or segmental wall 16 between .the two chambers 14 and 15, and when at or a'bove thisv level the oil or other fluid will also fill the annular groove 28 surrounding the upper end of the piston proper, forming a seal-to prevent air being drawn downwardly into the cylinder and to keep the cylinder properly sealed to 'prevent the fluid oozing upwardly between the piston and cylinder.

When the vehicle to which the device is applied, travels over uneven roads, passes over ruts, or strikes an obstruction, the body lof the vehicle will lower, due to its being supported by the springs of the vehicle, which become flexed; the result being that the casing moves downwardly with the'body of the vehicle and positions the actuating lever 54 at an angle. This causes the actuating arm 63 to assume a similar position, inV which the free end thereof more closely approaches the cap or cover 18 of the casing, with the result that the piston 23 is forced upwardly by the spring 26. This upward movement of the piston creates suction within the lower portion of the cylinder 15, also within the passage 17 connecting the `chamber 14 with said cylinder,

with the result that the spherical valve 42' is drawn inwardly against the action of the spring 51. This causes the annular space between said valve andthe sleeve or thimble 41 to be enlarged and permits the fluid in the chamber 14 to be drawn in -freely through said passage and into the cylinder, thereby lowering the level of the fluid in the chamber 14 and filling the enlarged lower` portion of the cylinder l5.

' When the chassis and body of the vehicle move upwardly, on what is generally termed the rebound, the casin vmoves upwardly with respect to the flexlble connection 16, with the result that the aetuatin lever 54 will'gradually assume a horizonta position, or a less inclined osition, or an oppositely inclined position, depending in the first instance on the position of said lever when -in normal position. However, as shown in the drawings the lever is -substantially in horizontal position when the parts are normal, and consequently after assuming a rearwardly inclined position when the body lowers and the spring is liexed, the recovery of the body will return said lever to horizontal position, with the result that the free end of the actuating arm 63 will again assume the position shown in Fig. 2, causin the piston 23 to be depressed against the oree of the spring 26. Under such conditions the oil is forced outwardly from the lower portion of the cylinder into the chamber 14. Immediately pressure is exerted in the .passage 17 by the lowering of the piston, the ball valve 43 will be forced outwardl into a fixed p'osition against the inner en of the stop stud 44, in which position said ball valve will again be spaced to restrict the passage between the same and the inner beveled end of the sleeve or thimble 41. It is clear therefore that when the piston rises, the suction created within the cylinder beneathl said piston will cause an enlargement of the annular space between the two relatively movable regulating elements within the passage 17,

as, when the piston lowers the annular space between the two relatively movable parts is restricted and a slow escape of the fluid from the cylinder occurs. This results in a slow upward recovering movement of the body portion of the vehicle, and naturally a slow recovery of the springs to normal position, thereby preventing upthrow of the vehicle body and assuring comfortable riding for the occupants.

If, on the downward movement of the piston, the pressure within the cylinder becomes excessive or reaches a point beyond that fixed by the counter-force of the spring 42, said spring will become compressed due to the force of the fluid against the inner end ofi the sleeve or thimble 41, and under"`such conditions said sleeve or thimble will be Ineved outwardly. This outward movement, however, is comparatively gradual and ex- Leashes eedingiy new., Danni the' inward move, s Ament of said sleeve or .t imble, the sphericitl vtalve is retainedin position betweenthe in'- ner end of the stop stud and the spiral spring provided so that'the fluid may escape from the cylinder, in accordance with the pressurel exerted therein b the lowering movehe force required vto overcome the expansion 'of the spring 44' is determined 'b any suitable means, and

` springs of di erentforce or. power are em- 'the bo ployed in vehicles of different makes, dependin upon the weight of the .frame and ycarried thereby, or the capacity load of the body. t It is to be noted. thatthe hardened steel disk does not completely fill said depression 29 and consequently the surrounding wall of said depression rises above the u per surface of said disk. When filling t e casing with oil .through the filling opening 21, oil will be delivered on said disk and be f retained thereon by the circular wall'sur- .rounding it so that, during the actuation of the piston, the contactin faces of said disk and the rounded end of t e actuating arm 63 will at all times be lubricated., This is a del'cided advantage, particularly when 'the level of the oil within the. casing is below the plane of said disk when the piston ism its tlowermost position, sincea quantity of oil 35,

or at least'a film of oil will at all times be retained in the circular depression above The sleeve or thimble A4:1 andthe spherical valve t3 may be referred 'to as springretained oppositely movable or yielding uid regulating or controlling e1ements, one of which is retained by asprlng more powerful than the spring of the other; these elements in referred form, opening andclosA I claim is 1. A shock absorber, comprising a casing having two chambers connected by a passage, 'oppositely movableelements within said passage controllin the flow of fluid therebetween from eac chamber to the other, and means for causing the fluid to flow from each chamber to the other through said passagen 2. A shock absorber, comprisin a casing having two chambers connected y a pas.- sage,v means in one of said chambers to cause the flow of Huid from each chamber to the other, and means within said passage comi prising two relatively movable parts normally restrictively spaced apart.

A shock'absorber,`comprising a casing containing a fluid and having two chambers connected by a passage, two spring-pressed elements within said passage normally restrictively spaced apart, means in one of said'chambers to' freely draw fluid through said passage from one of said chambers to the other chamber and to restrictively Vforce fluid from said other chamber into said rst mentioned chamber.

4. A shock absorber, comprising a casing having two chambers connected by a fluid passage, two spring-pressed elements normally spaced apart and adapted to be caused to separate to a greater degree when drawing fluid from one of said chambers into the other.,

5. Al shock absorber, comprising a casing having two chambers connected by' a passage, two spring-pressed elements within sald passage' normally spaced apart and adapted to be caused to separate 'to a greater degree when forcingI fluid from-one of said chambers into the other under pressure exceeding a predetermined high point.

,-6. A shock absorber, comprising a casing having a cylindrical bore therein serving as a cylinder and a chamber connected with said cylinder by a fluid passage, two relatively movable elements within said passage normally restrictively-spaced apart, springs of diii'erent power operating against said elements to maintain them in their restrictively spaced relation, a piston within said cylinder, and means for actuating said piston to cause'the same to reciprocate therein.

7. Ashock absorber, comprising a casing containin a fluid andy being divided into two cham ers, one of which serves as a cylinder, said casing having a fluid passage connecting said chambers, a spherical valve within said fluid passage, a sleeve within said passage from which said valve is normally restrictively spaced, a piston in the chamber serving as the cylinder, and' means to cause reciprocation of said piston, said spherical valve being caused to move away from said sleeve during the suction action of said piston and to return to restrictively spaced relation to said sleeve during the .pressure strokel of said piston, saidslee'v'e being movable away -from said valve when the pressure stroke of said piston creates a pressure in said passage exceeding a predetermined high point.

8. A shock absorber, comprising a casing containing a fluid and having a fluid chamber and a cylinder separated by a wall, a

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having a cylinder and passage connecting s'aid chamber, and cylinder, an adjustable stop carried by the. ca sing and having one end terminating within said passage, a valve spring-pressed against said stop, a sleeve within said passage retained in restrictively spaced relation to said valve, -a piston within said cylinder, fand means for causing reciprocation of said piston. A

9. A shock absorber, comprising a casing a piston within said cylinder, the cylindricalwall of said cylinder providing an oil groove around said piston to prevent the passage of air between the two and avoid seepage of the fluid therebetween.

10. A shock absorber, containing a fluid and cylinder and a chamber separated from said cylinder by a wall, said cylinder and chamber beingconnected by a passage having a shoulder therein, a sleeve within said passage having one end in contact with said shoulder, a spring to retain said sleeve comprisinga casing having an internal against said shoulder, a valve within said d passage normally in restrictively spaced relation to said sleeve, means to retain said valve in lnormal position, and a piston within said cylinder adapted for reciprocable movement and adapted to draw fluid from' said chamber into said cylinder and force fluid from said cylinder into said chamber, said valve being adapted to move away from l said sleeve when drawing fluid from said chamber into said cylinder.

11. A shock absorber, comprising a casing containing a fluid and having a chamber and a cylinder, said chamber and cylinder being connected by a passage having a shoulder, a bearing element within said passage in contact with said shoulder and arranged to permit the passage of fluid therethrough, a valve-within said passage, a stop element to hold said valve in restrictively open position, a spring between said valve and said bearing element to retain said valve against said stop element, and a piston within said cylinder adapted for reciprocable movement.

12. A shock absorber having a fluid containin casing divided by a wall to provide a flui -containing chamber and a cylinder, a passage between said chamber and cylinder, a pair of spring-pressed oppositelyopening elements in said passage normally spaced apart, and a-piston within said cylinder adapted for reciprocable movement.

13. In a shock absorber, a chamber and a cylinder adapted to contain a fluid land a assage connecting said chamber and cylin er, a pair of oppositely-closin elements w1'. thin said passage restrictive y spaced' apart, springs of different force acting against said elements to maintain the same 1n restrictively spaced relation# and a piston within said cylinder adapted for reciprocable movement.

14. A shock absorber, comprisin a casing containing a fluid and divide into a fluid containing chamber and a cylinder, a passage between said chamber and cylinder having a restricted portion, a spring-pressed valve in said passage, a stopelement against which said valve bears to maintain said valve in restrictively spaced relation to one end of said restricted portion, and a piston within said cylinder adapted for reciprocable movement.

15. A shock absorber, com rising a casing divided internally into a flhid containing chamber, a cylinder and a passage connecting saidV chamber and cylinder, a tapped opening in said casing having a cap threaded thereinto, a stop stud adjustably arranged through said cap and extendin into said passage, a spherical valve in sai passage, a spring in said passage acting against saidvalve to retain the same against said stop stud, and a piston reciprocable in said cylin- 16. A shock absorber, comprising a casing containing a fluid and divided to form a chamber and cylinder, a passage connecting' said chamber and cylinder, a stop stud extending from one wall of said cylinder into said passage, a sleeve iittin into said passage, a spring surrounding said stud and bearing with one end against said sleeve, a spherical valve held in restrictively spaced relation to said sleeve and spring-pressed against said stop stud, and a piston reciprocable within said cylinder.

17. A shock absorber, comprising a casing containing a fluid and having a chamber, a cylinder and a passage connectin said chamber and cylinder, one wall of sai casing having a tapped opening, a cap threaded into said opening, a stop stud adjustably threaded through said cap and extending into said passage, a jamb nut applied to said stop stud to retain the same in adjusted position, a sleeve fitting into said passage and having its bore beveled at its inner end, a coil spring surrounding said stud and bearing with opposite ends against said cap and said sleeve, respectively, a spherical valve spring-pressed against said stop stud and normally in restrictively spaced relation to the beveled portion ofsaid sleeve, and a piston reciprocable within said cylinder.

18. A shock absorber, comprising a casing containing a fluid and having a chamber, a cylinder and a passage connecting said chamber and cylinder, said passage being with oneend against the othershoulder, a spherical valve held in spaced relation to' the inner end of said sleeve, means to prevent saidvalve lying in contact with said sleeve, a spring surrounding the stud of said vsaid cylinder to said chamber, a piston within said cylinder, a spring between the bottom wall vof said cylinder and the lower end of said piston, a shaft extending transversely through said. casing, an actuating arm secured to said shaft-and bearing against the upper end of saidpiston, andan actuating lever extending from said shaft and adapted for connection with apart of the vehicle.

20g-AQ shock absorber, "comprising a casing containing a fluid and being divided into a chamber, a cylinder and a passage connecting said chamber and cylinderv means within said passage to cause ditlzerential .llovv of fluid in opposite directions, said cylinder, having -a reduced lowerl end, a

iston within'said cylinder having a shouler, a' coil spring bearingwithits lower end against the bottom vwall ofsaid cylinder and having its upper portion surrounding"the reduced lower end of said piston and the upper end thereof in contact 'with the shoulder of said piston.

2l. A shock absorber, comprising a casing containing a duid and ldivided bya' wall extending from the bottom of the casing up.-

wardly and terminating a distance from the top of said casing, the interior of the casmg at one side of said wall serving as a chamber and at the other side thereof a cylinder, -a passage connecting the lowerends of said chamber and cylinder andl having means therein to control the flow of fluid from the chamberto the cylinder and reversely, a pis- 4ton within said cylinder, a spring' within the lower portion of said cylinder acting against said piston, a shaft extending through the upper end of saidchamber, an actuating arm secured to saidshaft 'within'said casing and extending into the upper end of said cylinder, said arm being in contact with the upper end of said piston, andan actuating element outside of said casing extending from said shaft.

22. A. shock absorber, comprising a casl ing having a cylinder and a piston, said piston having a depression in its upper end, a wearing plate ttinginto said depression,

an actuating arm in contact with said wear- -ing plate, and a spring acting against said piston to retain the same in contact with said actuating arm.

23. A shock absorber, comprising a' casing containing a fluid and having a fluid chamber and a cylinder in communication at their upper ends and a fluid passage connecting the lower end of said chamber with the lower end of said cylinder, a piston within said cylinder, means within said passage to control the differential ow of fluid therethrough in opposite directions, a spring serving to hold said piston elevated, a crank shaft extending transversely through said casing at'the upper end of said chamber, an actuating arm secured to said crank arm and extending fromy said chamber into said cylinder and lying in contact with the upper end of said piston, and a lever outside of said casing extending from said shaft.

2 4. In a shook absorber, a casing containing a fluid and having a wall extending from its lower end upwardly and terminating a distance from the upper end of said casing, saidwall dividing said casing into a fluid-containing chamber and a cylinder, the upper portion of the cylinder being enlarged from a plane slightly beneath the upper edge of said wall and said wall havinga notch at its upper edge conforming tothe diameter of the enlarged upper portion of saidl cylinder, a piston within said cylinder normallyprojecting with its upper end into the enlarged portion thereof so as to lorm an oil groove around said piston at the lower end of the enlarged portion of said cylinder and at the 'upper end ol said-wall, a spring tending to force said piston upwardly, a shalt extending transverselyl through said casing at the upper end of said chamber, an actuating arm secured to said shaft extending through the 'opening connecting the upper end ol said chamber with said cylinder, said actuating varin .being in contact with the upper end of said piston, and an actuating lever extending from saidshaft.

25. ln a shock absorber, a casing having an internalcylinder, a pist-on within said cylinder and a iluid seal surrounding'the upper end of said piston when in normal position, said seal being maintained during the actuation of said piston.

26. A shock absorber, comprising a casing having an internalcylinder, a piston within said cylinder, and a iluid containing groove formed between said cylinder and the upper end of said piston when in normal position.

27.l In a shock absorber, a cylinder,l a piston within said-cylinder, and means embodied in the construction of said cylinder and piston to provide a sealing ring of fluid around said piston.

28. A shock'absorber'having a casing provided with a iiuid chamber and an enlarged Sil lll@

. drain opening, a cover for said casing having a filling opening, a plug for said filling opening, a piston within said cylinder, means for causing-reciprocation of said piston, and means within said passage to allow'the ree passage of fluid therethrough when said piston is moved in one direction and for retardbushing ing the passage of fluid therethrough when moving the piston in the opposite direction.

29. A shock absorber having a' casing provided with alined openings in opposite walls, a thimble-like bushing fitted into one of said openings and closing the outer endl of said opening, a sleeve bushing in the other opening of said casing, a shaft extending through said last-mentioned bushing and having one end thereof entered in said thimble-like bushing, a lever at theopposite end of said shaft outside of said casing,- an actuating arm securedV Lto said shaft between its bearings, and a piston within said casing against the upper end of which said actuating arm bears.

having alined openings in opposite walls and an internal cylinder, a thiInble-like bushing secured in one of said openings and closing the outer end thereof, a sleeve in the opposite opening terminating a distance from the outer end of said opening, a cup-like washer retainer titting into the. outer portion of said lastmentioned opening and receiving the outer end of said sleeve bushing, washers between the outer end of said sleeve bushing and the outer wall of said washer retainer, a shaft extending through vsaid retainer, washers, and sleeve bushing and having a reduced end portion fitting in said thimble bushing, an actuating lever at the opposite end of said shaft, an actuating arm secured to said shaft between said bushings and extending into.the upper end of said cylinder, a piston within said cylinder having its up- 4per Aend in contact with said actuating arm` and a sprin for maintaining said piston in contact lwlth said arm.v

31. In a shock absorber, a casing having 'a cylinder, a solid piston within said cylinder having a.circular depression at its upper end, a hardened disk within said depression, and an actuating arm having a rounded outer end lying in contact with said hardened disk.

32. A shock absorber," comprisin a casing containing fluid and havinga c amber, a cylinder and a passage connecting said chamber and cylinder,and opposing closure elements within said passage operating to permit the free flow of fluid through said wpassage in one direction and to retard the flow`of. fluid therethrough in the opposite direction.

33. A shock absorber, comprising a casing containing a fluid and having' 'a'chamber and a cylinder therein, a passage connecting said chamber and cylinder, a piston within said cylinder, and opposing closure elements within. said passage, said closure elements being retained in restrictively spaced relation under different spring pressures, one

of said closure elements moving away from the other under suction of said piston and movinr toward the other under pressure created by said piston, the other closure element moving away from its co-operating closure clement only when the pressure created by said piston exceeds a predetermined high point.

34QA shock absorber comprising a casing, a cylinder within said casino', a piston within said cylinder having a depression in its upper end, a wearing platefitting into said` depression and having its upper face in a plane below the upper edge of the wall surrounding said plate, an actuating arm in contact with said wearing plate, and a spring acting against said piston to retain the same in contact with said actuating arm.

35. In a shock absorber, a piston, and an actuating arm bearing against said piston to cause the same to `move in one direction, said piston embodying in its construction means to assure continual lubrication of the piston and actuating arm at their contacting point.

36. In a shock absorber, a piston having a' circular depression in its upper end, a wearing disk fitted within said depression and having its upper face in a plane below the upper edge of the wall surrounding said disk, and an actuating arm bearing against said wearing disk, the contact points of said disk and arm being lubricated by oil contained in said depression abovesaid disk.

37. In a shock absorber, a piston-and an aetuatmg arm bearing against said piston to cause the same to move, and means at the contacting point of said actuating arm and piston assuring continual lubrication of the two at said contacting point.

38. In a shock absorber, a piston and an actuating arm bearing against said piston to cause the same to move, one of said ele-` ments having means to retain a lubricant toassure continual lubrication at the point of contact of said actuating arm with said piston. l

39. Alshock absorber-comprising a casing having two chambers connected by a passage and supplied with a fluid, a piston within one of said chambers, and valve mechanism witlnn said passage comprising oppositely movable elements and springs retaining said elements in predetermined relation, said elements being controlled in movement against and valve mechanism within said assage the action of said springs by said'piston and having oppositely-pressed movable e ements the fluid between said piston and said valve between which the fluid is passed when mov- 10 mechanism. ing from each of said chambers to the other 5 40. A shock absorber comprisin a casing upon ei'ective manipulation of said piston.

" having two chambers `connected a pas- In testimony whereof I axm si nature.

sage, a piston within one of said c ambers, ADOLPH W. F. ZEL. 

